The 3rd Generation Partnership Project Long Term Evolution (3GPP LTE, or LTE for short) system controls a transmission of Physical Uplink Shared Channel (PUSCH) of a User Equipment (UE) by way of base station centralized scheduling.
In a LTE system, PUSCHs of multiple user equipments in a cell performs a frequency division multiplexing on an uplink system bandwidth, i.e. PUSCHs of different user equipments are orthogonal in frequency domain. While the base station schedules the transmission of a PUSCH of a user equipment by an uplink scheduling Grant (UL grant for short) signaling. The uplink scheduling grant signaling is carried in a Downlink Control Information (DCI) format 0, and is sent to the scheduled user equipment by the Physical Downlink Control Channel (PDCCH).
The information of the uplink scheduling grant signaling included in DCI format 0 is as follows:
1. Frequency hopping marker bit;
2. Resource block allocation and frequency hopping resource allocation;
3. Modulation and Coding Scheme (MSC) and Redundancy Version (RV);
4. New data indicator;
5. Transmit Power Control (TPC) command for scheduled PUSCH;
6. Cyclic shift for DM RS (de-modulation reference signal);
7. Uplink index (UL index), which only exists in a Time Division Duplex (TDD) system, and is used when the Uplink-downlink configuration is 0;
8. Downlink Assignment Index (DAI), which exists in a time division duplex (TDD) system, and is used when the Uplink-downlink configuration is 1˜6;
9. Channel quality Indicator (COI) request;
if the user equipment detects a PDCCH with DCI format 0, the user equipment sends the PUSCH on the assigned channel resource according to the uplink scheduling grant signaling included in the PDCCH.
The uplink resource allocation of the LTE system is in unit of resource block. A resource block is used to describe a mapping from a Physical Channel to a Resource Element (called as RE for short). Two resource blocks are defined in the system: a Physical Resource Block (called as PRB for short) and a Virtual Resource Block (called as VRB for short).
A Physical resource block occupies NSCRB consecutive subcarriers in frequency domain, and occupies NsymbUL consecutive symbols in time domain. Wherein, NSCRB=12, subcarrier spacing is 15 kHz, that is, the width of one PRB in frequency domain is 180 kHz. For a Normal cyclic prefix (called as Normal CP for short), NsymbUL=7, for an Extended cyclic prefix (called as Extended CP for short), NsymbUL=6, that is, the length of one PRB in time domain is a slot (0.5 ms). Thus, a PRB includes NsymbUL×NSCRB resource blocks. The index of the PRB in frequency domain is nPRB, wherein nPRB=0, . . . , NRBUL−1, NRBUL is the number of PRB corresponding to the width of the uplink system; the index pair of the RE is (k,l), wherein k=0, . . . , NRBULNscRB−1 which is a frequency domain index, l=0, . . . , NsymbUL−1 which is a time domain index, then
      n    PRB    =            ⌊              k                  N          SC          RB                    ⌋        .  
Taking conventional cyclic prefix as an example, a structure of a PRB is as shown in FIG. 1.
A virtual resource block has a structure and a size which are the same as the PRB. Two types of VRB are defined: Virtual Resource Blocks (VRB) of distributed type and Virtual Resource Blocks (VRB) of localized type. In resource allocation, a pair of VRBs located at two slots in a sub-frame (each sub-frame includes two slots) are distributed together, one pair of VRBs has an index nVRB.
The localized VRB is mapped to the PRB, i.e. nPRB=nVRB; in two slots in a sub-frame, the mappings from the localized VRB to the PRB are the same.
The distributed VRB needs to be mapped to the PRB according to a certain frequency hopping rule, and the frequency hopping rule is as follows:nPRB=f(nVRB,ns).
Wherein, ns=0, . . . , 19 is the slot number of a radio frame (10 ms). In two slots in a sub-frame, mappings from a distributed VRN to the PRB are different.
As shown in FIG. 2, in order to keep a single-carrier characteristic of the uplink signal, the PUSCH of the LTE system uses a consecutive resource allocation mode, i.e. a PUSCH of a user equipment occupies a section of consecutive bandwidth which is a part of the whole uplink system bandwidth in frequency domain. This section of bandwidth includes a group of consecutive PRB, wherein, the number of the PRB is MRBPUSCH, the number of the included consecutive subcarriers isMscPUSCH=MRBPUSCH·NscRB 
Base station assigns a set of VRBs for the user equipment by the uplink scheduling grant signaling. Specifically, a Resource Indication Value (RIV) is given in a resource allocation field of the UL grant. The RIV indicates initial location RBSTART and length LCRBs of a set of consecutive VRBs by a tree representation mode, wherein RBSTART is an index of an initial VRB of the set of consecutive VRBs, LCRBs is the number of VRBs included in the set of consecutive VRBs.
In an LTE system in a sub-frame, for a user equipment, at most one uplink scheduling grant signaling is sent to the user equipment by a PDCCH with DCI format 0.
An LTE-Advanced (called as LTE-A system for short) is the next generation evolution system of the LTE system. As shown in FIG. 3, the LTE-A system extends transmission bandwidth by adopting carrier aggregation technology, and each aggregated carrier is called as a “component carrier”. Multiple component carriers may be consecutive or may be non-consecutive, and are located at a same frequency band, or may be located at different frequency bands.
In an LTE-A system in a component carrier, a consecutive or non-consecutive resource allocation mode may be adopted for the PUSCH of the user equipment. The consecutive resource allocation refers to that the PUSCH of the user equipment occupies a section of consecutive bandwidth in a component carrier; the non-consecutive resource allocation refers to that the PUSCH of the user equipment occupies multiple sections of bandwidth in a component carrier, the sections of bandwidth are consecutive, each section of bandwidth includes a set of consecutive PRB, which is called as a cluster, as shown in FIG. 4.
The base station notifies the user equipment of a resource allocation of a physical uplink shared channel in a component carrier by an uplink scheduling grant signaling. When resource is allocated for the PUSCH using the non-consecutive resource allocation mode, the following problems exist.
The user equipment needs to be notified of the resource allocation of each cluster by an uplink scheduling grant signaling, however when there are multiple clusters, if an uplink scheduling grant signaling is sent for each cluster, then the reliability of transmitting the uplink scheduling grant signaling is reduced, thereby causing reducing of transmission performance of the PUSCH; if the resource allocation of all of the clusters are sent by an uplink scheduling grant signaling, then the number of clusters occupied by the PUSCH should be limited, which influences the flexibility of the resource allocation.